Auto Transmission Fluid Spew on 1993 Volkswagen Jetta

I have a 1993 Jetta with an automatic transmission. It intermittently has begun to spew transmission fluid, it does not appear to be coming from the dip stick, breather or the transmission cooler. Approximately 3/4 of a litre appears on top of the transmission when going up a hill. Has anyone else had this problem? Where might it be coming from?

Asked by for the 1993 Volkswagen Jetta
Are you sure this isn't coming from the vent? Is the fluid level correct? I believe the fluid level has to be checked while monitoring the transmission temperature, so it can be tricky to get the proper level.